The present invention relates in general to pollution control devices and efficiency devices in internal combustion engines. In particular, the present invention is directed to an apparatus to be installed in the positive crankcase ventilation (PCV) system of an internal combustion engine.
In internal combustion engines of the type employing reciprocating pistons which drive a crankshaft to deliver torsional power, for example, a common automobile engine, is well known that a portion of the combustion gases which are formed in the combustion chambers of the cylinders are driven by pressure, as well as the partial suction behind the pistons, passed the pistons toward and into the crankcase area of the engine. This phenomenon is known as "blow-by". These gases which are driven into the crankcase include combustion products such as carbon dioxide, carbon monoxide, as well as partially and completely unburned hydrocarbon fuel molecules. In an effort to improve engine efficiency and reduce automotive emissions, it has become the practice in the automotive industry to connect the crankcase with the air intake portion of the engine so as to draw from the crankcase a portion of these gases which is then directed into the air intake portion of the engine. The heated gases contribute to the operation of the engine by partially elevating the temperature of the incoming air and by passing the partial and unburned hydrocarbon fuel molecules through the engine to complete the combustion process.
As the gasses are passing through the crankcase, however, the gases mix somewhat with the oil vapors and particulate spray which are present in the crankcase during engine operation. These oil-based vapors, particulate materials, dirt and the like, when transmitted into the air intake portion of the engine, actually tend to contribute to the pollution generated by the engine, by contaminating the intake air, as the oil-based materials do not burn properly or completely in the combustion process. In addition, the oil-based vapor and particulate materials also may have a damaging effect on such components as the carburetor or fuel injectors.
As an additional consideration, there are several factors within the environment which contribute to poor combustion in an internal combustion engine, which results in higher emissions of pollutant compounds. These factors include the variable conditions of the atmospheric air, including, among other things, the relative amounts of oxygen and nitrogen, in the air the seasonal changes of ambient temperature, the emission of compounds from industrial smoke stacks and variable levels or exhaust fumes from both diesel and gasoline powered vehicles in road traffic.
The pollutants released by internal combustion engines are particularly troublesome since they may remain at ground level and further contaminate the air quality (oxygen content) flowing into the air intake of an engine, leading to even worse pollutant emission.
In addition, the intermixing of crankcase fumes with ambient intake air has the effect of still further lowering the overall percentage of usable molecular oxygen (O.sub.2), available for combustion, relative to the overall volume of gases taken into the cylinders, thus, adversely affecting the combustion efficiency.
Accordingly, it is desirable to provide an apparatus which will permit the recirculation of crankcase fumes back into the intake side of an internal combustion engine.
It is a further object of the invention to provide a crankcase fume recirculation system which is capable of separating out undesired oil-based vapors and particulate matter and the like, prior to returning the crankcase fumes to the intake side of the engine.
Yet another object of the invention is to provide a way to offset the effect of the lowering of the percentage of usable oxygen in the gases taken into the cylinders, which results when crankcase fumes are returned to the intake side of the engine, by making the oxygen in the air present in the crankcase more available for combustion.
These and other objects of the invention will become apparent in light of the accompanying specification, claims and drawings.